Difference Between Chordates and Non Chordates

Chordates and Non-chordates, both the terms are used for animals and they belong to the different phyla of the animalia kingdom. The major point to differentiate between chordates and non-chordates is that chordates have a spinal cord or backbone in their body structure whereas non-chordates are without backbone or notochord in their body structure.


Characteristic Features of Chordates

  1. Notochord is a supportive structure, stiff rod-like structure which is the characteristic of chordates.

  2. Dorsal hollow nerve cord is part of the Central Nervous System of chordates and it is concerned with stimulus and nerve impulses.

  3. Pharyngeal gill slits are an important part of the respiratory system and it gets perforated with gill slits.

  4. Post anal tail is present at the end of the anus in chordates in the form of a short extension.

Here is the tabular structure to highlight the differences and students will get an easy understanding to distinguish between chordates and non-chordates in their examinations.


Distinguish Between Chordates and Non Chordates


Chordates 

Non-Chordates

Notochord

Presence of cord or notochord.

Absence of cord or notochord.

Limbs

Limbs are two pairs.

Limbs may be more than two pairs.

Heart

Heart is ventral with hemoglobin, RBC and limbs. 

Heart is in a dorsal or lateral position with limbs.

Examples

Frog, fish, bird, reptiles, amphibians and mammals.

Cockroach, earthworms, flatworms, jellyfish, sponges, insects, water bears, and other arthropods, annelids and protozoans.

Post anal tail

They have post anal tail associated with them. 

No post anal tail is present in non-chordates.

Circulatory System

Chordates have a closed circulatory system.

Usually open circulation of blood takes place in non-chordates.

Nerve Cord

Dorsal, hollow and single nerve cord is present in chordates. The nerve cord is without ganglia.

Ventral, solid and double nerve cord is present. The nerve cord of non-chordates have ganglia.

Gill slits

Pharyngeal gill slits are present.

Pharyngeal gill slits are absent.

Respiration

Respiration occurs through the gills or lungs in chordates.

Respiration occurs through trachea, gills or body surface in non-chordates.

Body fluid

Hemoglobin is present in chordates.

Hemoglobin is absent, instead, hemolymph is present which is analogous to bloods in the vertebrates.

Germ layer

Talking about the germ layer, chordates are triploblastic.

Talking about the germ layer of non-chordates, they can be diploblastic, triploblastic or neither. 

Symmetry

These animals are bilaterally symmetric.

These animals can be bilateral, bi-radial, asymmetrical or radial.

Coelomates

They are true coelomates.

They can either be true coelomates, acoelomates or pseudocoelomates.

Exoskeleton

Exoskeleton is present in some of the chordates, for example, tortoises.

Exoskeleton is present in all non-chordates.

Endoskeleton

Endoskeleton is present in chordates.

Endoskeleton is absent in non-chordates.

Regeneration

Chordates have poor regeneration.

Non-chordates have good regeneration, mostly.

Anus

The anus of these animals is differentiated and opens before the last segment.

Anus in these animals is usually absent and if present, it opens on the last segment.

Brain

The brain of chordates is present, and located dorsal to the pharynx in head.

Brain is not as complex as that of chordates if present in some of the animals.

Organization

They have a body with an organ system.

Their body organization is protoplasmic to the organ system.

FAQs (Frequently Asked Questions)

1. Do Chordates Also Include Invertebrates?

Ans: Yes, some of the invertebrates fall under the category of chordates as notochord is present in them, however a proper backbone is lacking. Examples of these types of invertebrates include tunicates and lancelets.

2. How is Animal Kingdom Classified? Differentiate Between Chordates and Non Chordates.

Ans: Animalia kingdoms are classified as chordates and non-chordates where notochord is present in the former type and it is absent in the latter type.

3. Give Some Examples of the Non-Chordates.

Ans: Examples of the non-chordates are present in the phylum including Porifera, Cyonopera, Platyhelminthes, Aschelmenthis, Cyonophera, Annelida, Mollusca, Echinodermata, Hemichordata and Arthropoda. It includes earthworms, flatworms, sponges, jellyfish, cockroaches, etc.

4. What are the Divisions of Chordates?

Ans: Chordates can be divided into Urochordates, Cephalochordates and Vertebrates. Vertebrates are classified further into Agnathostomes and Gnathostomes. Gnathostomes can be Pisces (fish) and Tetrapoda on the basis of locomotive structure.

5. What are Some Examples of Different Phyla of Non-Chordates?

Ans: Sponges belong to Phylum Porifera, Hydra and Jellyfish belong to Coelenterata; Tapeworm belongs to Platyhelminathes; Earthworm and Leech to Annelida; Snail, Octopus and Pila to Mollusca; Fish, frog, snake, birds, monkey to Chordata; and Scorpion, fly and insects to Arthropoda, and so on.